Manhole structure constructing method, manhole structure water-stop flexible joint and manhole structure

ABSTRACT

A method is disclosed for constructing a manhole structure in which a manhole and a pipe are joined together by using a waterproof flexible joint. The joint includes a rigid cylindrical portion and a cylindrical flexible portion that has a covering portion to be fixed around an outer periphery of said pipe, a fixing portion fixed to an outer periphery of said rigid cylindrical portion and to be fixed to the manhole and a connecting portion connecting the covering portion to the fixing portion and made of an elastic material being capable of absorbing a displacement between the manhole and the pipe. The waterproof flexible joint is located around the outer periphery of the pipe, and the covering portion is fixed around the outer periphery of the pipe. Then, a filler for the manhole is poured around an outer periphery of the fixing portion.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for constructingmanhole structures, waterproof flexible joints for such manholestructures and the manhole structures thus constructed.

[0003] 2. Related Art Statement

[0004] There are a digging/reburying construction method, a jackingconstruction method, etc. as pipe-paving technique. According to thejacking construction method, a starting vertical hole and an arrivalvertical hole are first dug, and then a sewer pipe is pushed intohorizontally from the start vertical hole by means of a jack, while ahorizontal hole is being dug by a horizontal boring machine.

[0005]FIG. 4 is a vertical sectional view of a part of a conventionalmanhole structure 41. As shown in FIG. 4, a manhole 42 is placed in avertical hole. In order to minimize working, a steep pipe is generallyused as an earth-retaining wall when such a vertical hole is dug. In theconstruction of the manhole, a steel casing pipe serves as an outer moldframe 44, and the manhole 42 is formed between the outer mold frame 44and an inner mold frame 45.

[0006] When the manhole 42 is constructed within such a vertical hole,an end portion of a pipe 43 such as sewer pipe, as previously placed, isburied in a concrete wall 46 of the manhole as required from aninstallation space for the manhole 42.

[0007] Further, as shown in FIG. 4, an interface 47 between the pipe 43and the concrete wall 46 of the manhole is likely to serve as a passagefor leaking water. Under these circumstances, a sand-attached short pipein which sand 48 is glued around an outer peripheral surface 43 a of thepipe 43 is often used.

[0008] In the manhole structure 41 shown in FIG. 4, the concrete 46 isrigidly joined to the pipe 43, so that there is the possibility that thepipe 43 may be broken on earthquake or the like. Particularly when thepipe 43 is a Hume pipe or porcelain pipe, it is likely to be broken onground displacement.

[0009] When the pipe 3 is a flexible pipe such as a resin pipe, it isless likely to be broken by ground displacement, but there is still ahigh possibility that it may be broken. Further, the resin pipe is notbonded to the concrete, so that a water passage is formed when asand-attached short pipe is not used. Thus, the resin pipe has a problemin waterproof.

[0010] As shown in FIG. 4, in the case of the sand-attached short pipe,a fine gap 49 or the like is formed under the pipe 43 due to thedewatering sink before curing of the concrete 43 or after dryingshrinkage of the concrete 46 with lapse of years, thereby causing waterleakage.

[0011] Since the flexible pipe such as the resin pipe is particularlyflexible, it is likely to become flat due to ground pressure or thelike, so that formation of water passage cannot be completely preventedeven by using the sand-attached short pipe.

SUMMARY OF THE INVENTION

[0012] It is an object of the present invention to form a softconnection of the manhole structure through joining the manhole to thepipe with the water-proof flexible joint, so that the pipe can beprevented from being broken on earthquake or the like.

[0013] Further, it is another object of the present invention tocompletely prevent water leakage between the manhole and the pipe.

[0014] The present invention relates to a method for constructing amanhole structure in which a manhole and a pipe are joined together,said method comprising: preparing a waterproof flexible joint for themanhole structure, said waterproof flexible joint comprising a rigidcylindrical portion and a cylindrical flexible portion, said cylindricalflexible portion comprising a covering portion to be fixed around anouter periphery of said pipe, a fixing portion to be fixed to saidmanhole and a connecting portion connecting the covering portion to thefixing portion, said fixing portion being fixed to an outer periphery ofsaid rigid cylindrical portion, said connecting portion being made of anelastic material being capable of absorbing a displacement between themanhole and the pipe; locating the waterproof flexible joint around theouter periphery of the pipe; fixing the covering portion around theouter periphery of the pipe; and pouring a filler for the manhole aroundan outer periphery of the fixing portion.

[0015] Further, the present invention relates to a waterproof flexiblejoint for the manhole structure to be used in the above constructionmethod as well as to the manhole structure obtained by the above method.

[0016] The present invention is based on the knowledge that the manholestructure in which the joint portion between the pipe in the jackingmethod and the concrete manhole cast on site is made as a softconnection can be obtained by using the specific waterproof flexiblejoint for the manhole structure.

[0017] According to the present invention, the manhole structure, whichcomprises the manhole, the pipe and the waterproof flexible joint forthe manhole structure, is constructed by fixing the waterproof flexiblejoint around the outer periphery of the pipe and then pouring themanhole filler around the joint.

[0018] The waterproof flexible joint according to the present inventioncomprises the rigid cylindrical portion and the cylindrical flexibleportion. The rigid cylindrical portion is located on a radially outerside of the cylindrical flexible portion and serves to fix thecylindrical flexible portion to the manhole.

[0019] The cylindrical flexible portion comprises the covering portionto be fixed around the outer periphery of the pipe, the fixing portionto be fixed to the manhole, and a connecting portion connecting thecovering portion to the fixing portion.

[0020] According to the present invention, the fixing portion of thecylindrical flexible portion is fixed to the outer periphery of therigid cylindrical portion. The rigid cylindrical portion serves to fixthe fixing portion of the cylindrical flexible portion to the manhole.

[0021] According to the present invention, the manhole structure can beconstructed by fixing the covering of the cylindrical flexible portionto the outer periphery of the pipe and pouring the manhole filler aroundthe outer periphery of the fixing portion of the cylindrical flexibleportion.

[0022] In the present invention, the filler for manhole (hereinafterreferred to as “manhole filler”) includes concrete to be poured into amold frame for constructing the wall of the manhole on site or a fillerto be filled in a space between an inner face of a hole formed in thewall of an assembled manhole or the like and the waterproof flexiblejoint for fixing the waterproof flexible joint to the face of the hole.

[0023] In the present invention, the connecting portion of thecylindrical flexible portion is made of the elastic material capable ofabsorbing displacement between the manhole and the pipe. This connectingportion is located between the manhole and the pipe, and serves toabsorb the displacement between the manhole and the pipe.

[0024] In the present invention, the rigid cylindrical portion supportsthe fixing portion of the cylindrical flexible portion and fix thefixing portion to the manhole when the manhole filler is poured aroundthe outer periphery of the fixing portion of the cylindrical flexibleportion.

[0025] In the present invention, the rigid cylindrical portion keeps aspace between the fixing portion and the covering portion of thecylindrical flexible portion, and the connecting portion of thecylindrical flexible portion absorbs displacement between the manholeand the pipe within this space.

[0026] According to the present invention, after the waterproof flexiblejoint for manhole structure is fixed around the outer periphery of thepipe, the manhole filler is poured around the outer periphery of thewaterproof flexible joint. Thus, the manhole structure having themanhole and the pipe joined together by the soft connection can beextremely effectively constructed.

[0027] These and other objects, features and effects of the inventionwill be apparent upon reading the following description of the inventionin conjunction with the attached drawings, with the understanding thatany modifications, variations and changes can be made to the inventionby the skilled person in the art to which the invention pertains.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For a better understanding of the invention, reference is made tothe attached drawings, wherein:

[0029]FIG. 1 is a vertical sectional view of a part of one embodiment ofthe manhole structure according to the present invention;

[0030]FIG. 2 is a perspective view of a waterproof flexible joint forthe manhole structure according to the present invention;

[0031]FIG. 3 is a vertical sectional view of a part of anotherembodiment of the manhole structure according to the present invention;and

[0032]FIG. 4 is a vertical sectional view of a part of a conventionalmanhole structure.

DETAILED DESCRIPTION OF THE INVENTION

[0033] The present invention will be explained below in more detail.

[0034] (1) Manhole

[0035] In the present invention, manholes made of concrete cast on siteas well as other manholes produced preliminarily in factories, such asmake-up assembling manholes, can be used as manholes.

[0036] In the case of the make-up assembling manhole, a hole for theconnection with the pipe may be formed in the wall of the manhole onsite, but the hole is preferably formed in a factory or the like havingwell controlled quality management.

[0037] In the present invention, the manhole made of the concrete caston site can be formed by pouring the manhole filler in a mold frame onsite of the vertical hole.

[0038] (2) Pipe

[0039] In the present invention, the pipe is a pipe for connecting onemanhole to another manhole or the like. Typically, the pipe is a sewerpipe. Such pipes can be placed between at least two vertical holes bythe jacking method.

[0040] (3) Manhole Filler

[0041] In the present invention, the manhole filler is used to constructthe manhole on site or fixing the waterproof flexible joint to the innerface of the hole of the make-up assembled manhole.

[0042] As such a manhole filler, concrete, mortar concrete or the likecan be used at various quality levels without particular limitations. Ifthe space is narrow between the outer periphery of the rigid cylindricalbody and the inner face of the hole of the manhole, particularlynon-shrinkable mortar, resin mortar, epoxy resin or the like may befavorably used.

[0043] In the present invention, after the pipes are laid between atleast two vertical holes by the jacking method, the manhole isconstructed by assembling make-up concrete members inside the verticalhole and the manhole structure is constructed by fixing the waterproofflexible joint to the inner face of the cut hole of the assembledmanhole with the manhole filler after fixing the joint around an endportion of the pipe.

[0044] (4) Waterproof Flexible Joint for Manhole Structure

[0045] In the present invention, the waterproof flexible joint formanhole structure comprises the rigid cylindrical portion and thecylindrical flexible portion.

[0046] In the present invention, in the case of the manhole to beconstructed on site, the waterproof flexible joint can be attached to anend portion of the pipe placed by the jacking method or the like beforeforming the manhole wall of the concrete manhole.

[0047] Further, according to the present invention, in the case of theassembled make-up concrete manhole, after the manhole wall is formed,the waterproof flexible joint can be attached to the pipe placed by thejacking method. In this case, after another pipe is additionally joinedto an end of the pipe placed by the jacking method such that an end ofanother pipe may extend inside the manhole through the hole, thewaterproof flexible joint can be inserted between the hole of themanhole wall and another pipe.

[0048] (5) Cylindrical Flexible Portion

[0049] In the present invention, the cylindrical flexible portion isfixed to the outer periphery of an end of the pipe, and comprises thecovering portion to cover that end of the outer periphery of the pipe,the fixing portion to be fixed to the manhole, and the connectingportion to connect the covering portion to the fixing portion.

[0050] The fixing portion of the cylindrical flexible portion is fixedto the rigid cylindrical portion. The fixing portion can be fixed to therigid cylindrical portion by any of various fixing means withoutparticular limitations. As the fixing means, bonding or the like may beused. If durability or stability is considered, particularly a fasteningband or a tightening band may be favorably used.

[0051] The covering portion of the cylindrical flexible portion coversand is fixed to the outer periphery of an end of the pipe. The coveringportion may be fixed to that end of the outer peripheral portion of thepipe by any of various fixing means. Particularly a tightening band canbe favorably used.

[0052] As the connecting portion of the cylindrical flexible portion,various members may be used without limitation on their shape, etc. solong as the members are made of elastic materials capable of absorbingdisplacement between the manhole and the pipe within a space formedbetween the rigid cylindrical portion and the pipe.

[0053] In the present invention, the manhole is formed by pouring themanhole filler around the outer periphery of the fixing portion of thecylindrical flexible portion attached around the pipe.

[0054] In the present invention, the space between the inner face of thehole of the preliminarily formed manhole and the rigid cylindricalportion can be buried by pouring the manhole filler around the outerperiphery of the fixing portion of the cylindrical flexible portionattached around the pipe.

[0055] In the present invention, the fixing portion and the coveringportion of the cylindrical flexible portion are fixed to the manhole andthe pipe, respectively. By doing so, the constant space can be keptbetween the manhole and the pipe. Further, even if the manhole and thepipe exhibit different displacements to form a positional deviation, thecylindrical flexible portion can effectively absorb such displacementsto prevent the joining portion from being broken.

[0056] In the present invention, the cylindrical flexible portion can beformed from an elastic material. Any elastic material does withoutparticular limitations so long as it is soft enough to absorbdisplacement between the manhole and the pipe. Cylindrical flexibleportions made of various materials such as rubber may be used.

[0057] The cylindrical flexible portion may have a structure havingdouble cylindrical portions folded back midway. The double cylindricalportions of the cylindrical flexible portion serve as a covering portionand a fixing portion, respectively. The double cylindrical portions isconnected together by a connecting portion.

[0058] The cylindrical flexible portion may be provided with the rigidcylindrical portion at an inner side of the outer cylindrical portion sothat the outer cylindrical portion may not be folded inside.

[0059] (6) Rigid Cylindrical Portion

[0060] In the present invention, the rigid cylindrical portion can bemade of any of various materials in any of various forms withoutparticular limitations. In the present invention, a rigid pipe may beused. As such a pipe, a corrosion-resistant pipe made of stainless steelor the like may be favorably used.

[0061] The rigid cylindrical portion ensures the space to receive theconnecting portion of the cylindrical flexible portion between the rigidcylindrical portion and the pipe. For this purpose, the rigidcylindrical portion preferably has strength that makes it difficult tobe deformed with pressure of cast concrete, etc. In the presentinvention, the rigid cylindrical portion made of the same material asthat of the pipe may be used.

[0062] (7) Protective Member

[0063] In the present invention, a protective member may be used toprevent unfavorable flow-in of the manhole filler or to assuredly formthe space to receive the connecting portion of the cylindrical flexibleportion.

[0064] Such a protective member keeps a specific space between the rigidcylindrical portion and the pipe, between the rigid cylindrical portionand the covering portion of the cylindrical flexible portion or betweenthe manhole and the pipe.

[0065] Thus, the protective member may be provided between the rigidcylindrical portion and the covering portion of the cylindrical flexibleportion or between the inner mold frame to receive the manhole fillerand the connecting portion of the cylindrical flexible portion, forexample.

[0066] In the present invention, the protective member may be removedafter the manhole filler is poured and the manhole is formed.

[0067] (8) Jaw Portion

[0068] In the present invention, a jaw portion may be provided at theouter periphery of the fixing portion of the cylindrical flexibleportion. Such a jaw portion bites into the manhole filler so that it mayfix the fixing portion of the manhole. Further, the jaw portion servesto enhance adhesion between the fixing portion and the manhole filler.

[0069] Any material and any shape may be employed for the jaw portion solong as it bites into the manhole filler and is fixed inside the manholefiller. The jaw portion is preferably made difficult to be deformed bythe pressure of the cast manhole filler.

[0070] In the present invention, an adhesive or a pressure-sensitiveadhesive to bond the jaw portion to the manhole filler may be applied tothat surface of the jaw portion which contacts the manhole filler.

[0071] As the adhesive, a water-swelling rubbery adhesive, anon-vulcanizing butyl rubber-based adhesive or a water-swelling sealantmay be used. The non-vulcanizing butyl rubber-based adhesive ispreferred.

[0072] In the case of the waterproof flexible joint having the fixingportion with the jaw portion and the adhesive attached to the outersurface thereof, when the jaw portion to which the adhesive is appliedat the outer periphery of the fixing portion is buried in the manholefiller, water permeation between the manhole and the rigid cylindricalportion can be prevented, and water leakage through the interface of themanhole filler can be completely prevented.

[0073] The present invention will be explained in more detail withreference to the attached drawings.

[0074]FIG. 1 is a vertical sectional view of a part of one embodiment ofthe manhole structure according to the present invention. FIG. 2 is aperspective view of a waterproof flexible joint for the manholestructure according to the present invention. FIG. 3 is a verticalsectional view of a part of another embodiment of the manhole structureaccording to the present invention.

[0075] As shown in FIGS. 1 and 2, the manhole structure 1 has a manhole2, a pipe 3 and a waterproof flexible joint 4 for the manhole structure.

[0076] In the present invention, the manhole structure 1 is constructedby fixing the waterproof flexible joint 4 around the outer periphery ofthe pipe 3 and then pouring the manhole filler around the outerperiphery of the waterproof flexible joint 4.

[0077] The manhole structure 1 is provided with the waterproof flexiblejoint around the outer periphery of the pipe 3. The waterproof flexiblejoint 4 comprises a rigid cylindrical portion 5 and a cylindricalflexible portion 6.

[0078] The cylindrical flexible portion 6 comprises a covering portion 6a to cover the outer periphery of the pipe 3, a fixing portion 6 b to befixed to the manhole 2 and a connecting portion 6 c connecting thecovering portion 6 a to the fixing portion 6 b.

[0079] The fixing portion 6 b is fixed to the outer periphery of therigid cylindrical portion 5. The connecting portion 6 c is made of anelastic material capable of absorbing displacement between the manhole 2and the pipe 3.

[0080] The covering portion 6 a is fixed around the outer periphery ofthe pipe 3. The manhole 2 is formed by pouring the manhole filler aroundthe outer periphery of the fixing portion 6 b.

[0081] In the present invention, the fixing portion 6 b may be providedwith a jaw portion 7 as shown in FIGS. 1 and 2. The jaw portion 7 has anon-vulcanizing butyl rubber layer 8 at its surface. The jaw portion 7bites into the manhole 2.

[0082] In the present invention, the covering portion 6 a can be fixedto the outer periphery of the pipe 3 by using a pipe-tightening band 9as shown in FIGS. 1 and 2. The fixing portion 6 b can be fixed to therigid cylindrical portion 5 by using a rigid cylindricalportion-tightening band 10.

[0083] The manhole structure 1 of FIG. 1 is constructed in a verticalhole, and an earth-retaining casing 11 may be used as a mold frame forthe manhole filler.

[0084]FIG. 3 shows another embodiment of the manhole structure accordingto the present invention.

[0085] The manhole structure 21 is almost the same as the manholestructure 1 except that a waterproof flexible joint 24 for manholestructure is used.

[0086] The waterproof flexible joint 24 comprises a rigid cylindricalportion 25 and a cylindrical flexible portion 26.

[0087] The cylindrical flexible portion 26 comprises a covering portion26 a to cover a outer periphery of a pipe 23, a fixing portion 26 b tobe fixed to a manhole 22 and a connecting portion 26 c connecting thecovering portion 26 a to the fixing portion 26 b.

[0088] The covering portion 26 a at an inner side of the cylindricalflexible portion 26 is fixed to a pipe 23 as a projected pipe by meansof a tightening band 29.

[0089] Protective members 33 a and 33 b are inserted between the rigidcylindrical portion 25 and the covering portion 26 a and among an innermold frame 34 for the manhole filler, and the connecting portion 26 c,respectively.

[0090] The manhole filler such as concrete is poured between anearth-retaining casing 31 as an outer mold frame and an inner mold frame34, thereby forming a concrete wall of the manhole.

[0091] In the manhole structure of FIG. 3, a jaw portion 27 is providedat the fixing portion 26 on the outer side of the cylindrical flexibleportion 26, and the non-vulcanizing butyl rubber or water-swellingsealant 28 is set at a surface of the jaw portion 27, which bonds thejaw portion to the manhole filler. Thereby, waterproof can be enhanced.

[0092] In the present invention, waterproof can be also enhanced byattaching the non-vulcanizing butyl rubber or water-swelling sealant tothe outer periphery of the fixing portion of the cylindrical flexibleportion or the rigid cylindrical portion without providing the jawportion.

[0093] According to the present invention, the manhole structure inwhich the manhole and the pipe are joined together via the softconnection can be easily constructed by fixing the waterproof flexiblejoint for the manhole structure around the pipe and then pouring themanhole filler around the outer periphery of the waterproof flexiblejoint.

What is claimed is:
 1. A method for constructing a manhole structure inwhich a manhole and a pipe are joined together, said method comprising:preparing a waterproof flexible joint for the manhole structure, saidwaterproof flexible joint comprising a rigid cylindrical portion and acylindrical flexible portion, said cylindrical flexible portioncomprising a covering portion to be fixed around an outer periphery ofsaid pipe, a fixing portion to be fixed to said manhole and a connectingportion connecting the covering portion to the fixing portion, saidfixing portion being fixed to an outer periphery of said rigidcylindrical portion, said connecting portion being made of an elasticmaterial being capable of absorbing a displacement between the manholeand the pipe; locating the waterproof flexible joint around the outerperiphery of the pipe; fixing the covering portion around the outerperiphery of the pipe; and pouring a filler for the manhole around anouter periphery of the fixing portion.
 2. The constructing method setforth in claim 2, wherein said manhole is a concrete manhole cast onsite, said manhole is constructed by said filler.
 3. The constructingmethod set forth in claim, wherein said manhole is a make-up constructedmanhole, a hole is formed in a peripheral wall of the manhole, and saidfiller is poured into a space between the outer periphery of the fixingportion and a face of the hole.
 4. The constructing method set forth inany one of claims 1 to 3, wherein said fixing portion has a jaw portion,and said jaw portion bites into the manhole.
 5. A waterproof flexiblejoint for use in a manhole structure, said joint being adapted to join amanhole and a pipe and comprising a rigid cylindrical portion and acylindrical flexible portion, said cylindrical flexible portioncomprising a covering portion to be fixed around an outer periphery ofsaid pipe, a fixing portion to be fixed to said manhole and a connectingportion connecting the covering portion to the fixing portion, saidfixing portion being fixed to an outer periphery of said rigidcylindrical portion, said connecting portion being made of an elasticmaterial being capable of absorbing a displacement between the manholeand the pipe, the manhole being constructed by pouring a manhole filleraround the outer periphery of the filing portion.
 6. A manhole structureconstructed by the method according to any one of claims 1 to 4, saidmanhole structure comprising a manhole and a pipe joined together.
 7. Amanhole structure comprising a manhole, a pipe and a waterproof flexiblejoint for the manhole structure, the manhole and the pipe being joinedtogether by the waterproof flexible joint, said joint being adapted tojoin a manhole and a pipe and comprising a rigid cylindrical portion anda cylindrical flexible portion, said cylindrical flexible portioncomprising a covering portion to be fixed around an outer periphery ofsaid pipe, a fixing portion to be fixed to said manhole and a connectingportion connecting the covering portion to the fixing portion, saidfixing portion being fixed to an outer periphery of said rigidcylindrical portion, said connecting portion being made of an elasticmaterial being capable of absorbing a displacement between the manholeand the pipe, said covering portion being fixed to an outer periphery ofsaid pipe, and a filler for the manhole being poured around said fixingportion.